"It's really a diet that brings food back on to the plate that people thought they were not allowed to eat," said Ellen Kunes, the editor-in-chief of Health magazine and a co-author with dietician and nutrition expert Frances Largeman-Roth of "The CarbLovers Diet." Unlike other weight-loss plans that restrict carbohydrates, at least initially, the core of the CarbLovers diet is carbs and resistant starch, an ingredient in bananas, oatmeal, beans and lentils, wholegrain pasta, barley, brown rice, peas, polenta, potato chips and rye and pumpernickel bread -- foods the authors have been dubbed "carbstars."

"It acts like a fiber in the body and it does not get absorbed in the small intestine, and also at the same time it triggers fat-burning enzymes and helps to feel fuller," Kunes explained about resistant starch.

The 28-day diet includes a kickstart phase with carb-filled recipes totaling 1200 calories a day, followed by a 21-day immersion plan during which foods such as steak, french toast and chocolates are reintroduced.

Followers of the diet lost up to six pounds (2.7 kilos) in the first week and 50 pounds (22.7 kilos) over five months, according to the authors.

"The best thing you can do is to incorporate good carbs back on to your plate and that is the secret to losing weight and keeping it off," said Kunes.

In "The Lean Belly Prescription," Travis Stork, an urgent-care physician in Tennessee and the host of the TV daytime talk show "The Doctors" and Peter Moore, the editor of "Men's Health" magazine, focus on losing excessive abdominal, or belly fat.

"It's that visceral belly fat that hugs your internal organs, causing diabetes, increasing your risk of stroke and even cancers," Stork said in an interview.

"The concept of 'The Lean Belly Prescription' is good protein, good carbs and enjoying the foods you love. With simple tweeks you can eat the food you love and still lose weight."

With his pick 3 to lean plan Stork helps readers cut out nutritionally empty food and replace it with healthier version of the same food.

Coupled with moderate exercise Stork said the four-week plan will result in a lean belly and weight loss of as much as 15 pounds in a month.

"The Lean Belly Prescription is all about a practical approach to eating foods that taste great, being active, doing the things you love and losing weight while doing it. That's a concept that is missing in most diet books," he said. - Reuters